// balls.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

int main(int argc, char* argv[])
{
	double p=11340,d,r,v,w;
	scanf("%lf",&d);
	r=d/2.0/100.0;
	v=4.0/3.0*3.141592657*r*r*r;
	w=p*v;
	printf("%lf",w);
	return 0;
}

